Ad hoc networks are wireless and mobile networks without any fixed infrastructure. Researches in ad hoc networks field have reached a stage where experiments have become necessary. Most of the works in this area concern the design of protocols and their evaluation with theoretical analysis or with simulations. But the evaluation by simulations is not always realistic in ad hoc context due partly to the large dependence toward environmental factors. The main testbeds analyze the behavior of the studied routing protocols. But it is extremely difficult to differentiate in them the effects due to physical and MAC layers from the effects due to routing or others layers protocols. Since most of the current wireless cards implement the IEEE 802.11x standards, we investigate in this paper the services that could exactly be expected from this standard in ad hoc situations. We have developed a tool in order to deploy ad hoc scenarios and to monitor the traffic. From experiments, we extract the capacity of the radio medium, the asymmetry of the used cards, the effects of broadcast and unicast flows and the interfering range. All these parameters should enable a fine-tuning of the proposed protocols for ad hoc networks.